A motor vehicle seat is constituted by a molded pad, generally made of foam, covered by a cover, e.g. made of fabric or of leather. At present, in order to fasten a cover fabric on the outside surface of a motor vehicle seat pad, one or more retaining elements are placed in one or more reception grooves formed at the periphery of the pad, which retaining elements are suitable for co-operating with the covering by clip-fastening systems, by abutment systems, or indeed, more recently, by self-gripping systems where hooks engage hooks or hooks engage loops. These retaining elements are usually overmolded by the vehicle seat pad, at its periphery, at the time the pad is itself molded.
Patent application US 2003/0162008 describes such a retaining element that is generally U-shaped, having two side walls defining an inside space that is to receive a wire secured to a cover fabric for the vehicle seat. At its distal end, each side wall carries a projection that is to co-operate by abutment or clip-fastening with the wire so as to hold the cover around the vehicle seat pad.
The fastening of the wire by means of abutment or clip-fastening as obtained with that system is not sufficiently reliable. Furthermore, it is very difficult, if not impossible, to undo the fastening without damaging the cover.
The patent application published under the number WO 2011/089334 describes a retaining element of another kind comprising two side walls and a bottom defining a U-shaped groove, with hooks projecting from the bottom of the retaining element, which hooks are adapted to co-operate with loops or hooks of the cover.
During tests, it has been found that the self-gripping fastening obtained between the cover fabric and the hooks situated in the bottom of the retaining element is not entirely satisfactory, with the cover easily becoming detached from the retaining element when a traction force is applied thereto.